ATmega48A/48PA/88A/88PA/168A/168PA/328/328P
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Page
(0x7F)
(0x7E)
DIDR1
DIDR0
–
–
–
–
–
–
ADC3D
–
–
AIN1D
ADC1D
–
AIN0D
ADC0D
–
250
267
–
–
ADC5D
–
ADC4D
ADC2D
–
(0x7D)
Reserved
ADMUX
ADCSRB
ADCSRA
ADCH
–
–
–
(0x7C)
REFS1
–
REFS0
ACME
ADSC
ADLAR
–
MUX3
–
MUX2
ADTS2
ADPS2
MUX1
ADTS1
ADPS1
MUX0
ADTS0
ADPS0
263
266
264
266
266
(0x7B)
–
(0x7A)
ADEN
ADATE
ADIF
ADIE
(0x79)
ADC Data Register High byte
ADC Data Register Low byte
(0x78)
ADCL
(0x77)
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
TIMSK2
TIMSK1
TIMSK0
PCMSK2
PCMSK1
PCMSK0
Reserved
EICRA
–
–
–
–
–
–
–
–
(0x76)
–
–
–
–
–
–
–
–
(0x75)
–
–
–
–
–
–
–
–
–
–
–
(0x74)
–
–
–
–
–
(0x73)
–
–
–
–
–
–
–
–
(0x72)
–
–
–
–
–
–
–
–
(0x71)
–
–
–
–
–
–
–
–
(0x70)
–
–
–
–
–
OCIE2B
OCIE1B
OCIE0B
PCINT18
PCINT10
PCINT2
–
OCIE2A
OCIE1A
OCIE0A
PCINT17
PCINT9
PCINT1
–
TOIE2
TOIE1
TOIE0
PCINT16
PCINT8
PCINT0
–
164
140
112
75
(0x6F)
–
–
ICIE1
–
–
(0x6E)
–
–
–
–
–
PCINT19
PCINT11
PCINT3
–
(0x6D)
PCINT23
PCINT22
PCINT21
PCINT20
(0x6C)
–
PCINT14
PCINT13
PCINT12
75
(0x6B)
PCINT7
PCINT6
PCINT5
PCINT4
75
(0x6A)
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
(0x69)
ISC11
–
ISC10
PCIE2
–
ISC01
PCIE1
–
ISC00
PCIE0
–
72
(0x68)
PCICR
(0x67)
Reserved
OSCCAL
Reserved
PRR
–
(0x66)
Oscillator Calibration Register
37
42
(0x65)
–
–
–
–
–
–
–
–
(0x64)
PRTWI
PRTIM2
PRTIM0
–
PRTIM1
PRSPI
PRUSART0
PRADC
(0x63)
Reserved
Reserved
CLKPR
–
–
–
–
–
–
–
–
(0x62)
–
–
–
–
–
–
–
–
(0x61)
CLKPCE
–
–
–
CLKPS3
CLKPS2
CLKPS1
CLKPS0
37
55
9
(0x60)
WDTCSR
SREG
WDIF
WDIE
WDP3
WDCE
WDE
WDP2
WDP1
WDP0
0x3F (0x5F)
0x3E (0x5E)
0x3D (0x5D)
0x3C (0x5C)
0x3B (0x5B)
0x3A (0x5A)
0x39 (0x59)
0x38 (0x58)
0x37 (0x57)
0x36 (0x56)
0x35 (0x55)
0x34 (0x54)
0x33 (0x53)
0x32 (0x52)
0x31 (0x51)
0x30 (0x50)
0x2F (0x4F)
0x2E (0x4E)
0x2D (0x4D)
0x2C (0x4C)
0x2B (0x4B)
0x2A (0x4A)
0x29 (0x49)
0x28 (0x48)
0x27 (0x47)
0x26 (0x46)
0x25 (0x45)
0x24 (0x44)
0x23 (0x43)
0x22 (0x42)
0x21 (0x41)
0x20 (0x40)
0x1F (0x3F)
0x1E (0x3E)
I
T
H
S
V
N
Z
C
SPH
–
–
–
–
–
(SP10) 5.
SP9
SP8
12
12
SPL
SP7
SP6
SP5
SP4
SP3
SP2
SP1
SP0
Reserved
Reserved
Reserved
Reserved
Reserved
SPMCSR
Reserved
MCUCR
MCUSR
SMCR
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
PGERS
–
–
SPMIE
(RWWSB)5.
–
(RWWSRE)5.
BLBSET
PGWRT
SELFPRGEN
294
–
–
–
–
–
PUD
–
–
–
–
–
–
IVCE
PORF
SE
BODS(6)
BODSE(6)
IVSEL
EXTRF
SM0
–
45/69/93
55
–
–
–
–
WDRF
SM2
–
BORF
SM1
–
–
–
–
40
Reserved
Reserved
ACSR
–
–
–
–
–
–
–
ACBG
–
–
–
–
–
–
–
ACD
–
ACO
–
ACI
–
ACIE
–
ACIC
–
ACIS1
–
ACIS0
–
248
Reserved
SPDR
SPI Data Register
176
175
174
25
SPSR
SPIF
SPIE
WCOL
SPE
–
–
–
–
–
SPI2X
SPR0
SPCR
DORD
MSTR
CPOL
CPHA
SPR1
GPIOR2
GPIOR1
Reserved
OCR0B
OCR0A
TCNT0
General Purpose I/O Register 2
General Purpose I/O Register 1
25
–
–
–
–
–
–
–
–
Timer/Counter0 Output Compare Register B
Timer/Counter0 Output Compare Register A
Timer/Counter0 (8-bit)
TCCR0B
TCCR0A
GTCCR
EEARH
EEARL
FOC0A
COM0A1
TSM
FOC0B
COM0A0
–
–
COM0B1
–
–
COM0B0
–
WGM02
CS02
CS01
CS00
–
–
–
–
WGM01
PSRASY
WGM00
PSRSYNC
144/166
21
(EEPROM Address Register High Byte) 5.
EEPROM Address Register Low Byte
EEPROM Data Register
21
EEDR
21
EECR
–
–
EEPM1
EEPM0
EERIE
EEMPE
EEPE
EERE
21
GPIOR0
General Purpose I/O Register 0
25
10
8271BS–AVR–04/10